292 CLASS V. CEPHALOPODA. ORDER I. POLYTHALAMIA. 
phina, Polymorphina, Virgulina, Spheroidina, Gemmulina and Sagrina, and 
are considered peculiar in having the chambers alternately deposited into 
separate and distinct series, and furnished each on the inner side with a 
semilunar aperture. 
Examples. 
Pl. CCXCVII. Fig. 10. 
Textutaria sagittuta, D’Orbigny, Tableau Méthodique des Cépha- 
lopedes, p.97. Foraminiféres des Iles Canaries, pl. 1. f. 19 to 21. 
Polymorphum sagittulum, Soldani. 
Pl. CCXCVII. Fig. 11. 
TEXTULARIA BULLOIDES, Nobis. 
Spheroidina bulloides, D’Orbigny, ‘Tableau Méthodique des Céphalopodes. 
Cuvier, Régne Animal (Fortin’s edition), Mollusques, pl. 15. f. 9. 
Pl. CCXCVII. Fig. 12. 
TEXTULARIA CAPREOLUS, Nobis. 
Vulvulina capreolus, D’Orbigny, Tableau Méthodique des Céphalopodes. 
Cuvier, Régne Animal (Fortin’s edition), pl. 14. f. 11. 
NODOSARIA, Lamarck. 
Testa elongata, non spiralis, vel recta, vel arcuata, loculis aut convexis, 
aut depressis, singulatim superpositis. 
The genus Nodosaria, which we have selected to represent the remain- 
ing family of D’Orbigny’s Foraminifera, ‘‘ Les Sticostegues,” includes some 
of the largest of the series; their shells are either straight or curved, 
without any indication to become spiral, and consist of a greater or less 
number of chambers, piled one upon another upon the same axis. Seve- 
ral of them were known to Linneus ; his Nautili raphanus, fascia, rapha- 
nistrum, obliquus, legumen, radicula and siphunculus, were all referable to 
